| 摘要 |
Particles of linear aromatic polyesters, especially polyethylene terephthalate, are mixed with a pulverulent or granular concentrate containing a colouring matter finely dispersed in a linear polyester or copolyester which contains aromatic groups, has a molecular weight above 18,000 and a melting point above 150 DEG C., is soluble in a solvent boiling below 100 DEG C., and does not decompose at the melting point of the firstmentioned linear aromatic polyester, and the mixture is shaped in known manner into filaments, ribbons, monofils or foils. The acid component of the copolyester used to make the concentrate may consist for the greater part of terephthalic acid. The concentrate may be made by dissolving the polyester or copolyester in a solvent boiling below 100 DEG C., subsequently dispersing a pigment dyestuff of fine particle size in the solution so made, and then evaporating the solvent, while stirring. Alternatively, a dispersion of a dyestuff in an aqueous medium may be flushed from the aqueous phase into an organic solvent in which the polyester or copolyester used for making the concentrate has been or is subsequently dissolved, and the solvent evaporated from the solution to form the concentrate. A mixture of the particles of uncoloured linear aromatic polyester and the pulverulent or granular concentrate may be extruded to form a rod or narrow ribbon, which is then cut into small pieces and melt-spun. In examples, polyethylene terephthalate is mixed with concentrates containing, as colouring matters, carbon black, the dioxazine dyestuff made from 1 mol. of chloranil and 2 mols. of 3-amino-N-ethylcarbazole, a dyestuff made by condensing Bz-1-bromo-benzanthrone with pyrazole-anthrone and subjecting the product to alkaline fusion, and a copolyester made from 70 parts of dimethyl terephthalate, 30 parts of dimethyl isophthalate and the equivalent quantity of ethylene glycol, the solvent used being methylene chloride or ethylene chloride. Other specified colouring matters include iron oxide, cadmium pigments, ultramarine, phthalocyanines, vat dyes and anthraquinone derivatives. Specification 651,694 is referred to.
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